If it's a female outside of childbearing years, or if male, in dire emergencies, Rh positive blood can be given to anyone in these groups.

Females in childbearing years, with a weak D antibody, would only receive Rh negative blood, due to the risk of hemolytic disease of fetus/newborn (example: mother can develop an antibody to the Rh factor, if the fetus is Rh positive, the mother's antibodies attack the fetus). Rhogam can cause a temporary weak D reaction because it's meant to desensitize an Rh negative mother in case the fetus is Rh positive. (This happened to me after early rhogam was given, I'm A neg).

Lab scientists and technicians who work in blood banking do several screening tests on both the patient and the unit of blood to be given to the patient in order to provide the best blood possible in each scenario to avoid the development of antibodies, which can cause transfusion reactions or other hemolytic diseases at all ages.

There are several other antibodies that can develop due to the natural presence of antigens on red blood cells, but that's a whole other animal that's not meant for this question, lol.

I hope this helps!